I qt my 3" Achilles in a 10g doing TT for 3 weeks with prazi. Also did the same method for a 5" hybrid (Achilles/goldrim). After qt they live in separate 10g for 2+ weeks for observation. The 5" wasn't happy but its doable.
Best I'm going to be able to do is a 30L. Will throw in a couple of voyager stream pumps,for flow and I think will be OK. Got to find a healthy AT now!
LA puts them on sale for $120 or $130 sometimes.